The present invention relates to a method and an apparatus for obtaining an image or a waveform representing a physical property of an object such as a semiconductor wafer with an electron beam, and comparing the image or waveform with design information or an image obtained behorehand to judge a defect, measure the dimension of a specific place, shape information or the fabrication condition of an object such as a semiconductor wafer, or display an image, and relates to an inspected wafer and its fabrication line in the case where the wafer is the object in the apparatus.
A conventional method using an electron beam to judge a defect, measure shape information or the fabrication condition of an object such as a semiconductor wafer, or display an image is described in JP-A-5-258703 (U.S. Pat. No. 5,502,306), for example. The conventional method includes the steps of detecting secondary electrons generated at the time of exposure with an electron beam under the same condition, conducting scanning with the electron beam, obtaining thereby an image of secondary electrons, and judging a defect on the basis of the image.
It is now assumed that an object is formed by predetermined materials A and B. In the case where a certain acceleration voltage Eb of the electron beam is used, the secondary electron yield ratio xc3xa7 of the material A is largely different from that of the material B. In this case, a secondary electron image contrast is obtained, and inspection between the material A and the material B is possible. In the case where a specific acceleration voltage Ea is used, however, the secondary electron yield ratio xc3xa7 of the material A becomes equal to that of the material B. In this case, there is little contrast in an obtained secondary electron image and the image cannot be observed. In the conventional technique, due regard is not paid to such a charge-up phenomenon for each material to be observed.
In view of the above described problem, an object of the present invention is to provide an electron beam inspection method, and apparatus, for reducing the charge-up phenomenon caused when an object is exposed to an electron beam, obtaining a high-contrast signal representing a physical property by using secondary electrons or back-scattered electrons obtained from the object, and making it possible to inspect a minute defect at high speed and with high reliability.
Another object of the present invention is to provide an electron beam inspection method, and apparatus, for adapting the inspection condition to the charge-up phenomenon caused when an object is exposed to an electron beam, conducting inspection or measurement on the basis of an image signal representing a physical property by using secondary electrons or back-scattered electrons obtained from the object, and making it possible to inspect a minute defect at high speed and with high reliability.
Another object of the present invention is to provide an electron beam inspection method, and apparatus, for making it possible to inspect minute resist patterns and insulator patterns which are apt to be charged, with high reliability.
A further object of the present invention is to provide a semiconductor fabrication method and its fabrication line in which minute pattern defects on a semiconductor substrate such as a semiconductor wafer are inspected to improve the yield.
In order to achieve the above described objects, in accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and displaying a signal representing the detected physical change on display means.
In accordance with the present invention, a electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object according to a kind of a section structure on a surface of the object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object according to at least a kind of a material on a surface of the object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object according to a change of a section structure on a surface of the object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object according to a kind or a change of a section structure on a surface of the object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from the object in response to the controlled electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of presetting a proper acceleration voltage of an electron beam and a proper electric field in neighborhood of an object so as to correspond to a charge-up phenomenon on a surface of an object, exposing the object to the electron beam in such a state that the acceleration voltage is controlled to become the preset acceleration voltage, detecting in a sensor a physical change generated from the object in response to the electric field controlled to become the preset electric field, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of presetting a proper acceleration voltage of an electron beam and a proper electric field in neighborhood of an object so as to correspond to a charge-up phenomenon on a surface of an object according to a kind or a change of a section structure on the surface of the object, exposing the object to the electron beam in such a state that the acceleration voltage is controlled to become the preset acceleration voltage, detecting in a sensor a physical change generated from the object in response to the electric field controlled to become the preset electric field, and conducting inspection or measurement on the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, the charge-up phenomenon is grasped as a secondary electron yield efficiency in the electron beam inspection method. Furthermore, in accordance with the present invention, the acceleration voltage of the electron beam is in the range of 0.3 to 5 kV, in the electron beam inspection method. In accordance with the present invention, the electric field in the neighborhood of the object is 5 kV/mm or less, in the electron beam inspection method.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam on a sample, an electric field on the sample, a beam current, a beam diameter, an image detection rate (which is the clock frequency for reading image signals and which changes the beam current density), image dimensions (which is changed by changing the scan rate of the electron beam and consequently the beam current density), pre-charge (pre-charge on the sample is controlled by blowing an electron shower), discharge (discharge on the sample is controlled by blowing an ion shower), or a combination of them, exposing an object to the electron beam, detecting in a sensor a physical change generated from the object, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of controlling an acceleration voltage of an electron beam on a sample, an electric field on the sample, a beam current, a beam diameter, an image detection rate (which is the clock frequency for reading image signals and which changes the beam current density), image dimensions (which is changed by changing the scan rate of the electron beam and consequently the beam current density), pre-charge (pre-charge on the sample is controlled by blowing an electron shower), discharge (discharge on the sample is controlled by blowing an ion shower), or a combination of them so as to correspond to a kind or a change of a section structure on a surface of an object, exposing the object to the electron beam, detecting in a sensor a physical change generated from the object, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing an object to an electron beam, detecting in a sensor a physical change generated from the object, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change under inspection conditions such as inspection conditions (including a judgment standard and a measurement standard as well) corresponding to a charge-up phenomenon on a surface of the object.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing an object to an electron beam, detecting in a sensor a physical change generated from the object, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change under inspection conditions such as inspection conditions (including a judgment standard and a measurement standard as well) corresponding to a charge-up phenomenon on a surface of the object according to a kind or a change of a section structure on the surface of the object.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing an object to an electron beam, detecting in a sensor a physical change generated from the object, and extracting a structural feature of the object from a signal representing the detected physical change on the basis of a feature extraction parameter corresponding to a charge-up phenomenon on a surface of the object.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing an object to an electron beam, detecting in a sensor a physical change generated from the object, and extracting a structural feature of the object from a signal representing the detected physical change on the basis of a feature extraction parameter corresponding to a charge-up phenomenon on a surface of the object according to a kind or a change of a section structure on the surface of the object.
In accordance with the present invention, an electron beam inspection method includes the steps of providing a surface of an object with pre-charge (i.e., blowing an electron shower) or discharge (i.e., blowing an ion shower), exposing the object to an electron beam, detecting in a sensor a physical change generated from the object, and conducting inspection or measurement of the object on the basis of a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection method includes the steps of providing a surface of an object with pre-charge (i.e., blowing an electron shower) or discharge (i.e., blowing an ion shower), exposing the object to an electron beam, detecting in a sensor a physical change generated from the object, and extracting a structural feature on the surface of the object from a signal representing the detected physical change.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor. In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and display means for displaying a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the object according to a kind or a change of a section structure on a surface of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the object according to a kind or a change of at least a material on a surface of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the object according to a kind or a change of a section structure in an electron beam irradiation area on the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for effecting control so as to attain a proper acceleration voltage of the electron beam and a proper electric field in neighborhood of the object so as to correspond to a charge-up phenomenon on a surface of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, potential control means for effecting control so as to attain a proper acceleration voltage of the electron beam and a proper electric field in neighborhood of the object so as to correspond to a charge-up phenomenon on a surface of the object according to a kind or a change of a section structure on the surface of the object, a sensor for detecting a physical change generated from the object in response to the electric field controlled by the potential control means, upon exposure of the object to the electron beam with the acceleration voltage controlled by the potential control means, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, control means for controlling an acceleration voltage of an electron beam on a sample, an electric field on the sample, a beam current, a beam diameter, an image detection rate, image dimensions, pre-charge, discharge, or a combination of them, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, control means for controlling an acceleration voltage of an electron beam on a sample, an electric field on the sample, a beam current, a beam diameter, an image detection rate, image dimensions, pre-charge, discharge, or a combination of them so as to correspond to a kind or a change of a section structure on a surface of the object, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, inspection condition creation means for creating inspection conditions corresponding to a charge-up phenomenon on a surface of the object, image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor, under the inspection conditions created by the inspection condition creation means.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, inspection condition creation means for creating inspection conditions corresponding to a charge-up phenomenon on a surface of the object according to a kind or a change of a section structure on the surface of the object, image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor, under the inspection conditions created by the inspection condition creation means.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, feature extraction parameter creation means for creating a feature extraction parameter corresponding to a charge-up phenomenon on a surface of the object, and image processing means for extracting a structural feature of the object from a signal representing the physical change detected from the sensor, on the basis of a feature extraction parameter created by the feature extraction parameter creation means.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, means for providing a surface of the object with pre-charge or discharge, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, and image processing means for conducting inspection or measurement of the object on the basis of a signal representing a physical change detected from the sensor under inspection conditions.
In accordance with the present invention, an electron beam inspection apparatus includes an electron source, a beam deflector for deflecting an electron beam emitted from the electron source, an objective lens for focusing the electron beam emitted from the electron source upon an object, means for providing a surface of the object with pre-charge or discharge, a sensor for detecting a physical change generated from the object, upon exposure of the object to the electron beam, and image processing means for extracting a structural feature of the object from a signal representing the physical change detected from the sensor, on the basis of a feature extraction parameter.
In accordance with the present invention, a semiconductor fabrication line includes a plurality of processing systems for processing substrates, a control system for controlling the plurality of processing systems, an electron beam inspection system for conducting inspection on the basis of an image signal, the image signal being obtained by exposing a substrate processed by a predetermined processing system to an electron beam, the processing systems being controlled by the control system on the basis of an inspection result obtained from the electron beam inspection system.
In accordance with the present invention, a semiconductor fabrication method includes the steps of controlling an acceleration voltage of an electron beam and an electric field in neighborhood of an object, exposing the object to the electron beam with the controlled acceleration voltage, detecting in a sensor a physical change generated from a semiconductor substrate in response to the controlled electric field, and conducting inspection or measurement of the semiconductor substrate on the basis of a signal representing the detected physical change and thereby fabricating the semiconductor substrate.
In accordance with the present invention, a semiconductor fabrication method includes the steps of controlling an acceleration voltage of an electron beam on a sample, an electric field on the sample, a beam current, a beam diameter, an image detection rate, image dimensions, pre-charge, discharge, or a combination of them, exposing a semiconductor substrate to the electron beam, detecting in a sensor a physical change generated from the semiconductor substrate, and conducting inspection or measurement of the semiconductor substrate on the basis of a signal representing the detected physical change and thereby fabricating the semiconductor substrate.
In accordance with the present invention, a semiconductor fabrication method includes the steps of exposing a semiconductor substrate to an electron beam, detecting in a sensor a physical change generated from the semiconductor substrate, and conducting inspection or measurement of the semiconductor substrate on the basis of a signal representing the detected physical change under inspection conditions corresponding to a charge-up phenomenon on a surface of the semiconductor substrate and thereby fabricating the semiconductor substrate.
In accordance with the present invention, a result of the inspection or measurement is analyzed and fed back to a predetermined process, in the semiconductor fabrication method.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing a sample having a pattern formed on a surface thereof to an electron beam, controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the sample according to the material in an area on the sample exposed to the electron beam, detecting secondary electrons or back-scattered electrons generated from the sample, and thereby inspecting the pattern on the sample.
In accordance with the present invention, the acceleration voltage of the electron beam is controlled on the basis of a difference between the secondary electron yield ratio of the pattern and the secondary electron yield ratio of portions other than the pattern, in the electron beam inspection method. In accordance with the present invention, the electric field in the neighborhood of the sample surface is controlled on the basis of the secondary electron yield ratio of the pattern, in the electron beam inspection method.
In accordance with the present invention, an electron beam inspection method includes the steps of exposing a sample having a pattern formed on a surface thereof to an electron beam, controlling an acceleration voltage of the electron beam and an electric field in neighborhood of the sample according to the material in an area on the sample exposed to the electron beam, counteracting charges stored on the sample surface, detecting secondary electrons or back-scattered electrons generated from the sample, and displaying an image of the detected secondary electrons or back-scattered electrons on a screen, and thereby inspecting the pattern on the sample.
As heretofore described, the present invention makes it possible to reduce the charge-up phenomenon caused when an object is exposed to an electron beam, obtain a high-contrast signal representing a physical property by using secondary electrons or back-scattered electrons obtained from the object, and inspect a minute defect at high speed and with high reliability.
Furthermore, the present invention makes it possible to adapt the inspection condition to the charge-up phenomenon caused when an object is exposed to an electron beam, conduct inspection or measurement of the basis of an image signal representing a physical property by using secondary electrons or back-scattered electrons obtained from the object, and inspect a minute defect at high speed and with high reliability.
Furthermore, the present invention makes it possible to inspect minute resist patterns and insulator patterns which are apt to be charged, with high reliability.
Furthermore, the present invention makes it possible to inspect minute pattern defects on a semiconductor substrate such as a semiconductor wafer with high reliability and improve the yield.
Furthermore, the present invention makes it possible to inspect minute pattern defects on a semiconductor substrate such asa semiconductor wafer with high reliability and consequently makes it possible to inspect minute pattern defects on a wafer having minute pattern line widths in a fabrication line.